I want to subscribe to SD to operate a Piper Cub which we own with three pilots. I've read that there is a limitation of two IOS devices; can we however install it on three IPS devices as long as we respect not to operate on more than two IOS devices at the time?

Buying three subscriptions is too expensive for us.

Thanks for clarifying the max number of devices

Can't understnd people flying aircraft and not being able to pay for a SD subscription for themselves.
Eric